The present invention relates generally to optical microscopes, and more particularly to solid state optical microscopes.
Optical microscopes are typically designed with the human eye serving as a limiting factor. For example, the human eye is able to distinctly resolve only approximately 800 to 1,000 points per line on the width of a normal visual field. Because of this limitation, optical microscopes generally provide a resolvability only in this range. Optical microscopes coupled to electronic detectors are not new. In one such typical microscope, a point of light from the viewed object is defocussed and then made incident on a photomultiplier which is coupled to electronic processing means. Microscopes of this type provide a high signal-to-noise ratio, but the generation of digitized signals to provide an image of the object is exceedingly slow. In another microscope, a vidicon tube provides electronic representation of the microscope image, with the subsequent digitized signals generated at a high rate. However, the signal-to-noise ratio is compromised. In both types of microscope systems, the resolution characteristic of the total system is still limited to approximately 800 points per line.
The use of charge-coupling with optical microscopes, and in particular, the use of charge-coupled photodiodes with optical microscopes, is a unique feature of this invention. Such a combination with a high-resolution lens provides a wide field microscope with high resolution and a rapid data generation rate, such that the number of resolvable points per line is significantly improved, and is greater than 3,000.
Charge-coupling, as customarily defined, relates to the collective transfer of all the mobile electric charge stored within a semiconductor storage element to a similar, adjacent storage element by the external manipulation of voltages. The quantity of the stored charge in this mobile "packet" can vary widely, depending on the applied voltages and on the capacitance of the storage element, and the amount of electric charge in each packet can represent information. A more detailed description of charge-coupling is described by G. Amelio in Scientific American 230, pp. 23-31 (1974), incorporated herein by reference.